WASHINGTON — Mitch McConnell wanted a dance partner, and in Joe Biden he found one.

Lawmakers narrowly averted the worst of a fiscal crisis this week, largely thanks to behind-the-scenes negotiations between the Senate minority leader and the vice president – two Senate veterans and old-school politicians who reached a compromise no one seems to love but that enough members of both parties could accept.

The end to weeks of fevered negotiations came when a frustrated McConnell, who’s a Kentucky Republican, put out the call Sunday for someone to barter with after talks with Senate Majority Leader Harry Reid, D-Nev., had stalled. McConnell suggested Biden, who speedily returned to Washington from his home in Delaware.

By day’s end, the two had spoken more than three times by phone, and eventually they hammered out what would become a compromise to avert sudden economic peril.

“When the history books are written, we will see they made the difference,” said Rep. G.K. Butterfield, D-N.C. “They may not be political allies who see eye to eye, but they have mutual respect for each other and that’s what was needed.”

It’s not the first time the political odd couple – who served in the Senate together for more than two decades – has teamed up to broker deals, including a pact to extend the Bush-era income tax cuts in 2010 and another to lift the debt ceiling in 2011.

President Barack Obama, who was elected before he finished his first term in the Senate and has had frosty relations with Congress, has often turned to Biden as an ambassador to the chambers. Biden – whose public persona is often defined by a propensity for gaffes – spent 36 years as Delaware’s senator and knows how the Senate works and what it takes to make deals, observers say.

Biden shepherded the administration’s 2009 economic stimulus proposal, and he was asked last month to lead a task force to come up with suggestions on curbing gun violence in the wake of the school shootings in Newtown, Conn. His emergence as a deal-maker comes as speculation ramps up about whether he’ll mount a third run for president in 2016.

Observers say the shared Senate experience helped the two leaders talk to each other.

“Biden’s very much an institution man, as opposed to Obama, who pretty much passed through,” Senate Historian Donald Ritchie noted. McConnell and Biden “served together, and there’s a great deal of trust there that enables them to work together. They’ve known each other for decades, and they’ve taken the measure of each other along the way.”

Both men, said Jared Bernstein, a former economic adviser to Biden, come from an era of deal-making.

“These are two guys who remember how to compromise,” Bernstein said. “Unfortunately, that’s a lost art.”

Despite McConnell’s take-no-prisoners approach on the Senate floor – some Democrats revile him for his remarks in October 2010 that his priority was preventing Obama from winning a second term – Senate observers say he has a record of finding common ground.

Behind the scenes, McConnell repeatedly has shown a veteran senator’s knack for getting 80 percent of what he wants, not the 100 percent that younger members often insist on.

He’s often credited with finding a path to end the weeks-long impasse over raising the debt limit in August 2011. He first proposed the multi-stage approach to raising the limit, the outline of a plan that was later adopted.

He got all but five members of the Senate’s Republican caucus to vote for this week’s fiscal cliff fix.

For his part, Biden sold the plan to members of Congress in personal, and lengthy, trips to the Senate and the House of Representatives. Asked what powers of persuasion he’d employed, he quipped, “Me,” and said he’d reassured wavering senators, “I’m Joe. I’m your buddy.’”

In the House, Biden spent more than two hours answering questions from Democrats who were worried that the administration was giving up too much when it came to income levels for higher tax rates.

“I thought it was a filibuster,” Rep. Norm Dicks, D-Wash., quipped as he left the meeting.

In the end, just 16 House Democrats voted against it, and three in the Senate.

Late Tuesday, after the House had voted to send the legislation to Obama for his signature, the president took the stage at the White House, a beaming Biden at his side. Obama thanked legislative leaders, including McConnell. And he singled out Biden, calling him his “extraordinary” vice president.

“Everybody worked very hard on this and I appreciate it,” the president said, adding, “Joe, once again, I want to thank you for your great work.”

Email: lclark@mcclatchydc.com, dlightman@mcclatchydc.com; Twitter: @lesleyclark, @lightmandavid